Forged gear



March 25 1924 1,487,790 w. M. MANSFIELD ET AL FORGED GEAR,

2 Sheets-Sheet 1 Original Filed March 16. 1921 March 25, 1924. 1,487,790

W. M. MANSFIELD ET AL FORGED GEAR Original Filed March 16. 1921 2 Sheets-Sheet 2 5] vwozwcow ATE FFlCE- WARREN M. IJIANSFIELD, OF MOLINE, AND RAYMOND HENRY, OF ROCK ISLAND, ILLI- NOIS, ASSIG-NORS TO lvIOLINE PLOW COMPANY INCORPORATED, OF MOLINE, ILLI- NOIS, A CORPORATION OF VIRGINIA.

FOR-GED GEAR.

Original application filed March 16, 1921, Serial No. 452,749. Divided and this application filed May 8,

To all whom it may concern:

Be it known that we, WARREN M. MANS- FIELD and RAYMOND HENRY, citizens of the United States, residing at Moline, county of Rock Island, State of Illinois, and Rock Island, county of Rock Island, State of Illinois, respectively, have invented certain new and useful Improvements in Forged Gears, of which the following is a specifij cation.

The invention relates to a forged gear.

It relates particularly to large driving gears for use with tractors. The application is a division of our copending application, Serial Number 452,749, filed March 16, 1921. V

The large driving gears on the drive wheels of tractors are subjected to very severe strains because they transmit all the driving torque in all the various positions of the tractor wheels. They are also subjected to hard wear owing to the fact that tractors usually operate through dust and dirt. The gears must be hard to withstand the wearing action but, on the other hand must not be so brittle, that they will not withstand the stresses and strains to which they are subjected. Gears of cast iron and cast steel have been employed but have not satisfactorily met the requirements. Such gears either break too easily or wear out too quickly. The present invention relates to a forged gear.

The chief object of the invention is to provide an improved forged gear.

A more specific object is to provide a forged gear made in sections which may be readily connected together.

Other objects and advantages of the invention will appear from the specification and drawings.

An embodiment of the invention is illustrated in the copending drawings, in which Figure 1 illustrates a piece of metal stock out of which a section of the gear may be forged.

Figure 2 illustrates the shape of the gear section after the first operation.

Figure 3 shows the shape of the gear sec tion after another operation.

Serial No. 636,360.

Figure 4 is a side elevation of the gear section after another operation.

Figure 5 is a plan View of the tion illustrated in Figure 1.

Figure 6 illustrates the assembled gear.

In order that the construction of the gear may be clearly understood, the process of making it will first be described.

The metal stock out of which the gear is made is preferably in the form of a round bar 1, as illustrated in Figure 1. This bar is cut to the appropriate length and heated to a forging temperature.

The heated metal bar is then bent or shaped on the edge of a blocking die or. edger and placed in an impression in the blocking die. It is Worked back and forth between this impression and the edger until the bar is forged to the shape and form illustrated in Figure 2. The exact shape of the different portions of this piece may be varied to suit the requirements of the gear being made. The general principle followed is that the metal is thickened at certain places and thinned at others so that, when it is placed in other blocking and finishing dies, there will be the proper amount of metal at the proper places to completely fill the impression in the die so that the finished gear section will be completely filled out to the shape of the die. The section, as shaped in Figure 2, has a tong hole 2 at gear secone end, by means of which the piece may be handled.

The crudely shaped gear section is then reheated, if it has not retained sufficient heat to continue the forging process, and it is put in a finishing die where it is forged to the shape shown in Figure 8. The forging is continued until the die is filled and the diecess metal is forced out and forms a rough edge 10 called the flash. The gear section.

tion, as illustrated in Figure 3, is taken from the finishing dies to trimming dies where this flash 10 is trimmed off, leaving a completed forging gear section as illustrated in Figures 4 and 5.

This finished section forms one-sixth of a complete gear although it will beunderstood,

that the exact number of sections can be varied as required.

It will be observed that the conical projections 7, 8, and 9 are complementary to the holes 11, 12, and 13 respectively. For example, referring to Figures at, 5, and 6, if a. section exactly like the one illustrated in Figures l and 5 is fitted on to the one illustrated in Figure 6, the hole 11 of the second section would fit over the conical projection 7, and the holes 12 and 13 of the section illustrated in Figure would fit over conical projections 8 and 9 on the second sec- The hub portion of the one section overlaps the hub portion of the other and likewise a part of the peripheria-l portion of one section overlaps a part of the peripherial portion of the other section.

The sections are riveted together by means of the conical projections and the tapered holes. By referring to Figures i and 5, it will be noted that the holes are tapered in the opposite direction to the projections, so that when the projections are inserted in the holes, they may be riveted so as to firmly lock the parts together.

The gear is assembled by placing a forged gear section in an assembling press. lV hen the next gear section is completed, it is placed in the assembling press with the conical projections of one section inserted over the complementary tapered holes in the other section. The for ing operations and the assembling of the .orged gear sections in the assembling die are preferably car ried out rapidly and simultaneously so that the gear may be assembled before the forged sections become too cold. However, if they should become too cold in the assembling press, means is provided, in the nature of a gas jet or the like, for keeping the projections on the gear sections heated to a temperature that will permit them to be riveted.

fter a sufiicient number of gear sections have been placed in the assembling die to make complete gear, the dies are closed and the ends of the conical projections are riveted over to hold all the sections rigidly together.

When the gears are removed from the assembling press, they constitute a rigid forge-d gear in which the sections overlap one another and are held rigidly together by interval projections on one section riv eted to the other section.

The gear is then machinedin the same manner as if it were an interval gear and teeth are cut in its periphery.

near/{rec This process of making the gear makes it possible to use standard stock material; makes it possible to use relatively small forging hammers and dies, and it results in very little waste stock. If a large gear, such as is used in most tractors, were to be forged as a unit, the size of the hammers and dies would be prohibitive and the cost of the large pieces of metal stock would be high. here would also be excessive waste in the various parts that would have to be cut out of the large block of material.

ft is possible to obtain on the market, in the form of bars, a variety of the best gear steels. It is therefore possible to make the {rear herein described at a relatively small expense from a range of materials carried in stock at small expense. If it were necessary to carry in stock large blocks of metal, such as would necessary if the gear were to be forged as a unit, it would not only be very difficult to get a wide range of materials, but it would be also very costly and, in fact, too expensive to be practical.

The process is relatively simple and inexpensive since only a few simple forging operations are required. The gear sections are duplicates of one another. This simplifies the assembling operation since the operators do not have to use special care to see that special parts are fitted at the right place.

The gear is both strong and durable. It is strong because each section is a strong forged section and these sections are interlocked with one another by being overlapped. They are tightly riveted together by rivets of liberal size, interval with the forged sections. The gear is durable because it is made of selected gear material and that material is subjected to a forging operation which increases its durability.

It is to be understood that the gear shown is for purposes of illustration and that variations may be mane in its construction Without departing from the spirit and scope of the invention as defined by the appended claims.

"We claim:

.1. A. forged gear having more than two spokes, comprising a plurality of forged gear sections each comprising a spoke portion having a hub portion on one end and a rim portion on the other end, the hub and rim portions of one section partially overlapping those of the other, and means fastening the sections together.

2. A forged gear comprising a plurality of forged gear sections each comprising a spoke portion having a hub portion extendingin one direction from one end thereof and a peripheral portion extending in the other direction from the other end thereof, said sections having overlapping portions, and means connecting the sections together.

3. A forged metal gear having more than two spokes, comprising a plurality of gear sections each having a spoke portion with a hub portion on one end and a gear-tooth section on the other, said sections being united together by means of projections on one section extending through openings in the other and being riveted to hold the sections together.

4. A forged metal gear having more than two spokes. comprising a plurality of gear sections each of which comprises a spoke pOrtion having a hub portion projecting in one direction from one end thereof and a geartooth section projecting in the other direction from the other end thereof. the hub and gear-tooth portions of one section partially overlapping the hub and gear-tooth portions 'spoke having an arc-like hub portion pro-- jecting from one end thereof and an arelike gear-tooth section projecting from the other end thereof, said hub and gear-tooth sections having portions adapted to fit similar portions on adjacent sections so that a plurality ofsaid sections may be assembled to form a complete gear having more than two spokes.

In testimony whereof, We atfix our signatures.

WARREN M. MANSFIELD. V RAYMOND HENRY. 

